In conventional client-server environments, a client typically receives input data from a user and then transmits the input data to a server. The server then validates the input data received from the client. If the input data is invalid, the server notifies the client (and in turn the user) on why the input data is invalid. Based on this notification, the user attempts to provide valid input data or the client may restrict the user to provide only valid input data. In such conventional approaches, the client and the user do not know ahead of time which input data will be valid. Therefore, these approaches suffer from many inefficiencies including time wasted in entering invalid input data and sending notifications concerning invalid data to the client and user.
Other conventional client-server environments have attempted to address the above-noted inefficiencies by statically implementing validation rules on the server and the client. With this approach, the client can enforce validation rules on the client side, restricting the user to provide only valid input data, before transmitting the input data to the server. The server may validate input data received from the client and/or maintain and inform the client about updated validation rules. However, this approach suffers from other drawbacks. For instance, the developers of the server must expose the internal details of its services and provide voluminous documentations on exactly how the services operate so that various clients can be properly developed to be compatible with the server. In addition, this approach requires redundant implementations of the validation rules on both the server and the client. Furthermore, because the validation rules are statically implemented on the client, any change in the validation rules on the server requires corresponding updates to all the clients, which requires time-consuming administration and can often result in inconsistencies between the validation rules on the server and on the client.
These and other disadvantages of conventional data validation systems and techniques create a need for improved validation methods and systems. There is also a need for improved validation methods and systems in client-server environments where, for example, a client requests validation rules from a server on the fly, and the server dynamically generates up-to-date validation rules.